The video was posted on YouTube on Monday under the user name BITcrash44. By Wednesday, it had generated more than 800,000 views and had been mentioned on Web sites like Gizmodo, Gothamist, Salon and NBC New York. One Web site even listed it as the most popular viral video on Twitter.

The multitudes who have seen the video have become swept up in an intense debate around one question: is it real? Well, it’s a fake. And the reaction is exactly what James Percelay and Michael Krivicka wanted when they produced the video as part of a promotion for the soon-to-be-released film “Limitless.”

The two men, founders of a viral marketing company called Thinkmodo ( http://thinkmodo.com/ ), are tapping into a growing desire among marketers to attract and keep the attention of online viewers with videos that get shared on social Web sites like Twitter, YouTube and Facebook. The strategy for Thinkmodo is to make videos that viewers will think are clever and authentic without overtly pushing or mentioning a product, Mr. Percelay said. More: http://www.nytimes.com/2011/03/17/business/media/17viral.html